> For the complete documentation index, see [llms.txt](https://xojo.gitbook.io/add-ons/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xojo.gitbook.io/add-ons/stackview/version-2/details/viewcontroller.md).

# ViewController

{% hint style="info" %}
Class (inherits from [ContainerControl](https://documentation.xojo.com/api/deprecated/containercontrol.html))
{% endhint %}

## Constants

#### 🔒 kExpansionPerTick As Number = 30

Measure/Step (Pixel) while a ViewController collapse/expand.

#### 🔒 kPeriod As Number = 30

Period (ms) while a ViewController collapse/expand.

## Events

| [Collapse](/add-ons/stackview/version-2/details/viewcontroller.md#collapse) | [Expand](/add-ons/stackview/version-2/details/viewcontroller.md#expand) |
| --------------------------------------------------------------------------- | ----------------------------------------------------------------------- |

#### Collapse

Fires if a ViewController is collapsed.

#### Expand

Fires if a ViewController is expanded.

## Methods

| [Expand](/add-ons/stackview/version-2/details/viewcontroller.md#expand) | [Init](/add-ons/stackview/version-2/details/viewcontroller.md#init-collapsedheight-as-integer-expandedheight-as-integer) |
| ----------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ |

#### Expand(value As Boolean)

Expand or collapse a ViewController.

**Parameters**

| *value* | A [Boolean](https://documentation.xojo.com/api/data_types/boolean.html) specifiying the state of the ViewController. |
| ------- | -------------------------------------------------------------------------------------------------------------------- |

#### Init(collapsedHeight As Integer, expandedHeight As Integer)

Set a ViewController’s collapsed and expanded height.

**Parameters**

| *collapsedHeight* | An [Integer](https://documentation.xojo.com/api/data_types/integer.html) specifiying the height of the collapsed ViewController. |
| ----------------- | -------------------------------------------------------------------------------------------------------------------------------- |
| *expandedHeight*  | An [Integer](https://documentation.xojo.com/api/data_types/integer.html) specifiying the height of the expanded ViewController.  |

## Properties

#### Animated As Boolean

Animate a ViewController while collapsing/expending.

#### Expanded As Boolean

Return state of a ViewController.